Liquid filtration-mass transfer system



May 19, 1970 I. J.- KUGELMAN EFAL 3,512,639

" LIQUID FILTRATION-MASS TRANSFER SYSTEM Filed 001;. 18, 1967 2Sheets-Sheet 1 IA'WiNTORS Irwin J. Kugelmun Joseph B. Hellmann ZZMATTORNEY May 19, 1970 I. J. KUGELMAN ETA!- 3,512,639

LIQUID FILTRATION-MASS TRANSFER SYSTEM 2 Sheets-Sheet 2 Filed Oct. 18,1967 INVENTORS Irwin J. Kugelmun BY Joseph B. Hellmonn Fig. 2.

ATTORNEY United States Patent Ofice 3,512,639 Patented May 19, 19703,512,639 LIQUID FILTRATION-MASS TRANSFER SYSTEM Irwin Jay Kugelman,Union, N.J., and Joseph B. Hellmanu, Queens Village, Jamaica, N.Y.,assignors to American Standard llnc., New York, N.Y., a corporation ofDelaware Filed Oct. 18, 1967, Ser. No. 676,167 Int. Cl. BOld 33/20 US.Cl. 21080 23 Claims ABSTRACT OF THE DISCLOSURE This invention relates toa method and apparatus for countercurrent contact between a liquidstream and a bed of solid particles for the purposes of removingcomponents either from the liquid stream or from the solid particles.The invention is applicable to such processes as the treatment ofsanitary or industrial wastes with powdered or granular coal, thetreatment of water supplies by filtration through beds of granular sand,the softening of hard waters by means of particles of ion exchangeresins, the decoloration of sugar solutions by means of activatedcarbon, the extraction of soybean oil with solvents, as well as otherlike processes which will be obvious to those skilled in the art.

The invention provides a method and apparatus wherein a bed of solidparticles is maintained in a compact condition by essentially completelyfilling the vessel in which it is contained, in which method andapparatus the spent portion of the bed is periodically or intermittentlyremoved by placing the bed of solid particles and the entrapped liquidunder an absolute pressure such that the solid particles and anyentrapped solids and liquid will issue forth when said particles arecommunicated with an external vessel at less than said pressure. Thespent bed material is discharged from the lower surface of the bed. Newbed material is then supplied to the upper surface of the bed. 1

CROSS REFERENCES TO RELATED APPLICATIONS Four other related patentapplications, assigned to the same assignee and filed concurrentlyherewith are identifiled as follows: R. S. Bevans, SN 676,193, filedOct. 18, 1957; 'R. S. Bevans, ISN 676,266, filed Oct. 18,1957; J. B.Hellmann, SN 676,180, filed Oct. 18, 1957; and I. I. Kugelman, SN676,192, filed Oct. 18, 1957.

BACKGROUND OF THE INVENTION This invention is useful in various liquidtreating applications, such as the treatment of sewage, industrialwaste, and municipal water supplies.

The closest known prior art is US. Pats. 3,244,561 and 3,200,067.

SUMMARY The invention contemplates an improved counter-current apparatusand method for compacting and periodically or intermittentlyreplenishing a solids-liquid contacting bed. Compaction is accomplishedby essentially completely filling a vessel with solid particles. The bedis maintained continually serviceable by periodically removing andreplenishing the solid particles or batches of the solid particles.

THE DRAWING FIG. 1 illustrates schematically a sectional view takenthrough a form of an apparatus embodying the invention.

FIG. 2 illustrates schematically a sectional view taken through a secondform of an apparatus embodying the invention.

GENERAL DESCRIPTION In the drawing of FIG. 1, there is shown an upstanding vessel including two main sections 10 and 40, each of which istapered at both ends and these two sections are joined together by avalve 36. Both sections 10 and 40 contain granular coal or otherappropriate material designated respectively 12 and 42. The section 10may be regarded as the treatment section and section 40 as the chargingsection. Liquid influent, such as raw sewage or industrial waste, is fedinto an inlet line 13, then raised in pressure by a pump 16 connected toa line 14, the line 14 having suitable perforations 18 within thetreatment section 10, and the influent is delivered through theperforations 18 to the lower region of the bed 12 which is containedwithin the treatment section 10'. A valve 38 is inserted in line 14 andoperated, whenever desired, to interrupt the supply of the influentliquid. An outlet line 26, which includes a valve 24, is coupled to theupper region of the section 10. The portion of line 26 encompassedwithin section 10 also has suitable perforations 22 to prevent any ofthe bed material 12 from entering line 26. The valve 24 within line 26is operated periodically to interrupt the flow of the eflluent liquidfrom output.

intervals, fed through a line 44, then raised in pressure by a pump 46and supplied by another line 48 to the top of the charging section 40. Avalve 50 is shown coupling the charging section 40' to a storage hopper-60. Valve 50 is operated intermittently to allow some of the solidparticles, such as coal, to be supplied to the top of the chargingsection 40. Another valve 20 is located in the lowermost region of thetreatment section 10 so that some of the bed material, particularly someor all of the portion which has become clogged or otherwise spent, maybe removed intermittently and, if desired, delivered to another. station(not shown) where it may be regenerated for reuse in the column ordisposed of or utilized for other purposes, for example, as a fuel.Valve 34 located below perforated line 14 may be periodically opened toremove liquid from vessel 10 to aid in bed compaction.

The reference characters T1, T2 and PS schematically represent a timefactuator, a cycle-timer .and a pressure switch, respectively, which maybe coupled in any well known manner to the controllable devices, such aspump 16 and valve 38, the valves 20, 36 and 34 and the thepump 46 andoutlet control valve 24.

Detailed description of method of FIG. 1

Vessel 10 is initially essentially completely filled with theappropriate granular material, e.g. coal, with the and apparatus spacesbetween particles filled with liquid. Vessel 40 is initially filledeither partially or completely with the ap propriate granular materialwith any space, which is unfilled by the granular material, filled withliquid. Under normal operating conditions, influent liquid, such asrawsewage, will be supplied through the line 13 and raised in pressure bypump 16 for transmission through line 14,

then through the perforations 18 in that line, into the With the valve36 connecting the columnar sections and 40 closed and the outlet valve24 open, liquid which has been filtered or treated in its travelvertically up through the bed 12 will enter the outlet line 26 throughthe perforations 22 therein and be discharged into the holding tank 28.The perforations 22 of the discharge pipe are appropriately screened toprevent bed particles or filtering material from escaping from the bed12. The treated liquid is the desired end product, and it may beretained by tank 28 or in any other appropriate receptacle (not shown),or it may be discharged into a lake or river. The treated liquid productis continuously fed to the tank 28 except during the very brief periodsof the surge cycles when clogged bed material is discharged.

The upfiowing liquid traversing the bed 12 exerts an upward drag forceon the bed 12. This force will increase as the pore spaces becomeclogged by particles or solids extracted from the influent liquid. Whenthe drag force exceeds the combined forces resulting from the buoyantbed weight of the bed 12 and from the friction due to the contactbetween the bed 12 and the wall of the treatment section 10, the bedwill be caused to move up, that is, to be uplifted, or the spacesbetween particles will be caused to increase, i.e. the bed will becaused to be fluidized. However, the bed 12 is restrained from anyordinary movement or expansion within the treatment vessel 10 becausethe grandular particles essentially completely fill vessel 10. The bed12 will instead be caused to compact. The additional compaction with thebed 12 will increase the filtration efficiency within the bed 12.

As the pore spaces of the bed become clogged with solids removed fromthe liquid, the discharge pressure of the pump 16 required to force theliquid through bed 12 will increase.

The pressure resulting from the clogging of the pore spaces may beallowed to increase up to but not exceeding the limit of the capacity ofthe pump 16, at which limit it will be necessary to remove the cloggedlayer or layers of the bed 12 from the vicinity of perforations 18 inorder to reduce the influent pressure and permit the system to continueto function. It is one of the objects of the invention, as alreadynoted, to periodically or intermittently remove from the vicinity ofperforations 18 that portion of the bed 12 that may be more denselyclogged or otherwise spent and to discharge it from vessel 10. Bydischarging bed material positioned below perforations 18, space will beprovided for the entire bed 12 to move downward and subsequently placeunclogged or unspent bed material in the vicinity of perforations 18.Thus, the inlet pressure will be substantially reduced.

The discharge of clogged bed materia is accomplished by stopping theoperation of pump 16, closing the inlet valve 38 and the discharge valve24. Thus, when the pump 16 is de-energized and the valves 24 and 38 areclosed, the liquid within the bed 12 will remain substantiallystationary. Then the connecting valve 36 is openend and, shortlythereafter, the recycle pump 46 is started. The pump 46 will cause someof the previously treated liquid in tank 28 to be discharged through thelines 44 and 48 into the top of the storage section 40. suflicientoperating time is then allowed to enable the pump 46 to build upsuflicient hydraulic pressure throughout vessels 40 and 10. When apredetermined pressure has been achieved, the discharge valve 20 at thebottom of vessel 10 is opened. This will allow the previously clogged orspent bed material below the performations 18 to be discharged throughthe valve 20 accompanied by some amount of fluid. As the spent bedmaterial is released via the open valve 20, fresh material will passfrom the vessel 40 into the treatment section 10 and replenish an amountof material that is substantially the equivalent of that which has beendischarged by valve 20. Valve 20 is maintained in the open position fora period of time equal to or less than the period of time required forthe pressure throughout the vessels 40 and 10 to come to equilibriumwith the pressure in the vessel into which coal and clogged solids arebeing discharged. After valve 20 closes, the valve 34 is opened tofurther compact the bed and complete the filling of vessel 10 ifnecessary. The opening of valve 34 enables some of the liquid within thebed 12 to be discharged and this will serve to compact the bed 12 to thepoint where it will again act as an improved filtering medium. Pump 46is then de-energized, and valves 34 and 36 are closed. The system isthen returned to normal operation by the re-energizing of pump 16 andthe opening of valves 38 and 24. The spent bed material, including thesewage solids accompanying it which have been discharged through valve20, may be disposed of by burning or otherwise.

While the countercurrent system involves an intermittent flow ofinfluent upwardly between the perforated sections 18 and 22 and anintermitten downfiow or discharge of clogged material of bed 18 throughthe exit valve 20, in certain trial arrangements employing thisinvention, the upward flow of the effluent continued for periods varyingbetween 30 and 180 minutes, but the surge cycle, for the discharge ofspent coal, that is, the interval between the opening and closing ofvalve 36, lasted no more than about half a minute. Hence there were longfiltering periods and relatively short surge cycles. Thus, the equipmentperformed filtering operations during a high percentage of the availableoperating time.

For automatic operation, the pressure switch P.S., which is connected tothe input line, may control a programmed stepping switch or a programmedseries of timers represented by T2 in FIG. 1. These switches and timerswill be started in operation upon the influent pressure rising to apredetermined value. On the other hand, the timer actuator T1 mayalternatively start the switches and timers after a predeterminedinterval, such as 30, 60 or minutes. The cycle of operations willinvolve the following sequential steps:

(1) De-energize the influent pump 16.

(2) Close the inlet and outlet valves 38 and 24.

(3) Open the interconnecting valve 36.

(4) Start recycle pump 46.

(5) Open the bed discharge valve 20.

(6) Close the bed discharge valve 20.

(7) Open the liquid discharge valve 34.

(8) De-energize the recycle pump 46.

(9) Close the liquid discharge valve 34 and connecting valve 36.

(10) Energize the influent pump 16. 11) Open the inlet and outlet valves38 and 24.

The discharge of liquid via valve 34, as above described, might beomitted if desired, but the system will function considerably better ifthis step of the operation is retained. If the discharge via valve 34were omitted, the bed within chamber 10 might not be sufliciently filledwith the granular medium and it might tend to fluidize on the resumptionof normal operation. The efiiciency of the operation would thereby bereduced. Tests have indicated that the employment of valve 34 for fluiddischarge has significant merit.

FIG. 1 depicts the spent material as being discharged through valve 20into vessel 64 which is substantially at atmospheric pressure. Thisrequires that during the purging operation that the entire beds 12 and40 be brought up to a pressure somewhat above atmospheric pressure. Thisis done by closing valves 38 and 24 and operating pump 46 until thedesired pressure is reached. Valve 20 is then opened.

It is also possible to accomplish the purging of spent bed material bydischarging such material through valve 20 into a vessel maintained atless than atmospheric pressure. This is shown in FIG. 2 which depictsvessel 66 maintained at less than atmospheric pressure by means ofvacuum pump 68, communication between the vacuum pump 68 and vesselbeing provided by pipe 70. A valve 72 is provided so that materialwasted from the column 10 and delivered to the vacuum chamber 66 may beremoved when required.

Certain examples employing the invention were aS follows:

(1) Raw sewage was passed through a column 6 feet high having an insidediameter of 3% inches and packed with -10 to +100 mesh anthracite coalat a flow rate of 30 gallons per hour per square foot of column crosssection. The run lasted 17 days. Periodically during the run, coal andsewage solids were discharged by placing the entire column underpressures which varied from 20 to 40 psi. and opening valve 20 toatmospheric pressure. Suspended solids removal averaged 88.4%, chemicaloxygen demand removal averaged 73.9%, coal removal averaged 53.7 poundsper 1,000 gallons of sewage treated.

(2) Raw sewage was passed through a column 6 feet high having an insidediameter of 3% inches and packed with l to +100 mesh antracite coal at aflow rate of 45 gallons per hour per square foot of column crosssection. Periodically coal and sewage solids were discharged by placingthe entire column under pressure which varied from 20 to 40 psi. andopening valve 20 which was connected to a tank which was maintained at15 inches of vacuum. Suspended solids removal averaged 90.7% chemicaloxygen demand removal averaged 68.5%, coal removal averaged 59.5 poundsper 1,000 gallons of sewage. The run was conducted for four consecutivedays.

While the operation of the apparatus has been described with referenceto a bed of material, such as coal, for the treatment of sewage, theapparatus is equally and fully suitable for use in any other solidsliquid contact process. Some examples of these are: filtration of waterfor industrial or domestic use through sand or coal, demineralization orsoftening water with ion exchange resins, de-colorization of sugarsolutions with activated carbon, removal of soluble organic matter fromwater and wastes with activated carbon, and the extraction of soybeanoil with solvents.

It will be apparent that the vessels 10 and 40 may be constructed ofmetallic, plastic or other materials of sufiicient strength to withstandthe pressures to be developed in the system.

The fluid inserted from line 48 to the top of vessel 40 has beendescribed as previously treated fluid obtained from tank 28. It will bereadily apparent that any other fluid, e.g., water, may be substitutedfor treated fluid. The salient property is that the inserted fluidtransmitted through line 48 be subjected to a predetermined pressure andthat such fluid have little or no chemical reaction on the normalcontents of vessels 10 and 40 or on the solids or fluids in thesevessels.

While this invention has been shown and described in certain particularembodiments merely for the purpose of illustration, it will beunderstood that the general principles of this invention may be appliedto other and widely varied organizations without departing from thespirit of the invention or the scope of the appended claims.

What is claimed is:

1. In a method employing apparatus including a vessel having a verticalcolumn essentially completely filled with granular material, the methodof filtering influent material bearing sewage, which consists ininserting the influent material into the vessel at a point near thebottom thereof so that the influent material flows countercurrentagainst the granular material, removing efiluent liquid product from apoint near the top of the vessel, intermittently interrupting theinfluent material and the efliuent product, inserting a portion of thepreviously discharged effiuent liquid product into the upper portion ofa second vessel positioned above said first vessel, and applyingpressure to the first Vessel through said second vessel for dischargingsome of the material from said first vessel.

2. The method recited in claim 1 in which the liquid product insertedinto the upper portion of the said vessel is replaced by water.

3. The combination of a vertical vessel essentially completely filledsubstantially continually with granular material through which influentmaterial is driven under pressure upwardly through the entirecross-section of said vessel and is discharged as liquid product fromthe upper region of said vessel, an apparatus for intermittentlycleaning clogged granular material from the bottom of said vessel, saidapparatus including means for shutting off the incoming influentmaterial as well as the discharging liquid product, and means forapplying some of the liquid product to said vessel under sufiicientpressure in order to drive the clogged material out of the bottom ofsaid vessel, and additional means for removing liquid from said vesselto improve the compaction of the granular material within said vessel.

4. The combination recited in claim 3 in which the part of the liquidproduct to be applied to the vessel to drive clogged material out of thebottom of the vessel is a fluid which has no chemical interaction withthe granular material contained within the vessel.

5. The combination recited in claim 3 in which the apparatus alsoincludes means for discharging some of the applied liquid from thebottom of the vessel for facilitating the compaction of the material insaid vessel.

6. The combination recited in claim 5 including, in addi tion, means forinserting additional granular material into the top of the vessel toreplace the material discharged from the bottom of the vessel and tomaintain the vessel substantially filled with said material.

7. The combination of a treatment cylinder and a storage cylinder, bothcylinders being filled with granular material and being positioned invertical alignment with each other so that the storage cylinder ispositioned above the treatment cylinder, a normally closed valvecoupling said cylinders to each other, a valve-controlled intake linepositioned within and near the bottom of the treatment cylinder, anoutput line near the top of the treatment cylinder for receivingeffluent material as it reaches near the top of the treatment cylinder,and apparatus for disposing of clogged granular material accumulatednear the intake line within the treatment cylinder, said apparatusincluding cooperating means for shutting off the valve-controlled intakeline and for closing the output line, means for opening the normallyclosed coupling valve, and means for pumping some of the efiluentmaterial under pressure to the storage cylinder so as to drive theclogged granular material out of the normally closed opening at thebottom of the treatment cylinder and to move some replacement materialfrom the storage cylinder into the treatment cylinder.

8. The combination defined by claim 7 in which said apparatus alsoincludes a drain line at the bottom of the treatment cylinder and meansfor transmitting fluid through said drain line.

9. The combination of a vertically upstanding treatment vessel filledwith granular material which is closed at its bottom, an intake linepositioned near the bottom of said vessel for receiving influentmaterial, an output line positioned near the top of said vesselreceiving treated material moving upwardly through said vessel and fordischarging eifluent product from said vessel, means for disposing ofthe clogged granular material accumulated near the bottom of saidvessel, said means comprising means for shutting off both the intake andoutput lines and for feeding some of the efliuent product undersubstantial pressure to said vessel so as to drive clogged materialwithin the vessel out of the bottom of said vessel, and a storage vesselcoupled between the treatment vessel and the output line.

10. The combination recited in claim 9 in which the intake line and theoutput line each have a perforated section within the treatment cylinderincluding means serving to prevent any of the granular material fromentering said lines.

11. The combination defined by claim in which said disposing meansincludes a drainline near the bottom of the treatment vessel which maybe opened to release some of the fluid from the bottom of the vessel tofacilitate the compaction of said material in said vessel.

12. The method of treating liquid bearing sewage, which consists oftransmitting the influent liquid upwardly through a bed of granularmaterial, removing the treated liquid from a point near the top of thesame bed, intermittently re-inserting some of the treated liquid underpressure to the top of the bed through a storage space, andintermittently discharging some of the material from the bottom of thebed, whereby infiuent liquid to be treated is moved only in an upwardlydirection through the bed and the bed is moved step-by-step only in adownward direction.

13. The method defined in claim 12, in which some of the liquid withinthe bed is discharged near the bottom of the bed so as to facilitate thecompaction of the bed.

14. The combination of a liquid-treating cylinder filled with granularmaterial, an intake line for feeding to the cylinder liquid to betreated and to be moved only in an upward direction through thecylinder, an output line near the top of the cylinder for receiving thetreated liquid, means for periodically pumping some of the treatedliquid under pressure into the top of the cylinder, means forperiodically discharging some of the material from the bottom of thecylinder, and means for periodically discharging some of the liquid fromthe bottom of the cylinder, to facilitate the compaction of the materialwithin the cylinder.

15. The combination recited in claim 14 including, in addition, meansfor periodically supplying replenishing material to the top of thecylinder to replace the discharged material, whereby the cylinder willbe maintained substantially filled with material at all times.

16. Apparatus for the treatment of a liquid bearing sewage, comprising avertical cylinder filled with particles or material, means for causingthe liquid to be treated to move unidirectionally upwardly through thecylinder and for the material within the cylinder to be movedperiodically downwardly through the cylinder, an input line positionednear the bottom of the cylinder for feeding the liquid to be treated tothe bottom of the cylinder, an output line near the top of the cylinderfor receiving treated liquid, a pump for periodically pumping some ofthe treated liquid under pressure to the top of the cylinder, a valve atthe bottom of the cylinder through which material within the vessel maybe discharged, means for intermittently opening said valve in order todischarge said material from the bottom of the cylinder, and separatemeans for periodically discharging some of the liquid from the bottom ofthe cylinder to facilitate the compaction of the material within thecylinder.

17. Apparatus for the treatment of a liquid bearing sewage in accordancewith claim 16 including, in addition, vacuum apparatus coupled to saidvalve at the bottom of the cylinder, said vacuum apparatus increasingthe pressure differential between the two sides of said valve at thebottom of said cylinder so as to facilitate the discharge of saidmaterial through said valve.

18. Apparatus for the treatment of a liquid bearing sewage in accordancewith claim 17 including, in addition, a second valve for dischargingliquid from the bottom of the cylinder in order to aid in the compactionof the material within the vessel.

19. A liquid treatment apparatus, comprising a vessel substantiallyfilled with granular material for the treatment of incoming liquids,normally closed upper and lower valves for said vessel through whichsaid granular material may be, respectively, supplied to or removed fromsaid vessel, a closed receptor into which the lower valve discharges,means for supplying liquid under pressure through said upper valve torender the internal pressure within the vessel significantly higher thanthe internal pressure within said receptor, and means responsive to thedifference between the internal pressures of the vessel and the receptorfor discharging substantially spent material from said vessel into saidreceptor.

20. A liquid treatment apparatus according to claim 19, in which thereceptor includes means to maintain a pressure which is substantiallybelow atmospheric pressure.

21. A liquid treatment apparatus according to claim 19, in which thereceptor includes means for normally maintaining pressure.

22. A liquid treatment apparatus according to claim 19, including meansby which liquid is fed into the vessel through the upper valve to raisethe pressure within the vessel to the range of twenty to forty p.s.i.

23. A liquid treatment apparatus according to claim 19, including meansby which the pressure within said receptor is maintained at a value ofabout 15 inches of mercury.

References Cited UNITED STATES PATENTS 293,750 2/1884 Hyatt 210-l891,620,431 3/1927 Bramwell 2l0l89 2,801,966 8/1957 Meates et a1 210-268 X3,056,743 10/1962 Eichhorn et al. 210189 X 3,270,886 9/1966 Sackett210-l89 3,276,585 10/1966 Kalinske 2lO--279 X 3,287. 426 11/1966Entringer 210-189 X JOHN W. ADEE, Primary Examiner US. Cl. X.R.

